pains in the stomach, side, or abdomen, possibly radiating to the back

pale skin

pinpoint red spots on the skin

rapid, shallow breathing

red skin lesions, often with a purple center

red, irritated eyes

sores, ulcers, or white spots in the mouth or on the lips

swollen glands

unexplained bleeding or bruising

unpleasant breath odor

unsteadiness or awkwardness

unusual bleeding or bruising

upper right abdominal or stomach pain

vomiting of blood

weakness in the arms, hands, legs, or feet

Some of the side effects that can occur with leflunomide may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

A 58-year-old female with longstanding rheumatoid arthritis experienced parastomal collection and stomach perforation coincident with leflunomide therapy. The patient had been taking leflunomide 20 mg per day and prednisone 5 mg per day. She presented with complaints of a one day history of abdominal pain. A CT scan showed a parastomal collection and stomach perforation. She proceeded to surgery for drainage of the collection and repair of the perforation. The leflunomide therapy was subsequently stopped and cholestyramine washout administered. She required prolonged hospital stay, with total parenteral nutrition and intravenous antibiotics.[Ref]

Respiratory

A 54-year-old female with rheumatoid arthritis experienced acute respiratory failure coincident with leflunomide therapy. She developed the adverse event 2 weeks after cessation of 6-weeks treatment with leflunomide. She was diagnosed with interstitial pneumonia, probably induced by leflunomide because acute respiratory failure was preceded by hypertension and elevated serum liver enzyme concentration. She showed dramatic improvement with cholestyramine and prednisolone.[Ref]

Cardiovascular

Dermatologic

A 46-year-old woman with erosive and refractory rheumatoid arthritis (RA) developed sudden focal hair loss (alopecia areata) after 3 weeks of treatment with leflunomide. Three months after leflunomide had been stopped due to poor control of RA, the patient's hair was slowly recovering.

A 61-year-old female with severe rheumatoid arthritis experienced cellulitis coincident with leflunomide therapy. The patient had been taking leflunomide 20 mg alternate days and prednisone 10 mg per day. She presented with cellulitis of the left foot that had not responded to oral amoxicillin/clavulanic acid. Isolates from a plantar ulcer showed Staphylococcus aureus. Despite appropriate antibiotic treatment, the infection progressed rapidly and she developed necrosis of the left foot. She proceeded to surgical debridement with forefoot amputation and skin graft. On day 4 of admission, leflunomide therapy was discontinued and cholestyramine washout administered. She had a prolonged hospital stay that required 5 further debridement procedures.[Ref]

Metabolic

Hypersensitivity

A 69-year-old male with a 19-year history of rheumatoid arthritis experienced hypersensitivity pneumonitis coincident with leflunomide therapy. Three months after being administered leflunomide 20 mg once a day, he presented with a 1-month history of progressive dyspnea, decreased appetite, and weight loss. The temporal association and resolution following discontinuation suggest leflunomide was the causative agent.[Ref]

Endocrine

Ocular

Renal

Hepatic

A 69-year-old male with stable rheumatoid arthritis experienced liver tuberculosis coincident with leflunomide therapy. The patient had been taking leflunomide 20 mg daily as monotherapy for 31 months. He presented with a 2 month history of anorexia, 10 kg weight loss, fever, and night sweats. A CT scan showed multiple low attenuation lesions in the liver. Initial liver biopsy was nondiagnostic, revealing only minor changes with no evidence of infection. Although Mycobacterium tuberculosis culture was negative, due to strong clinical suspicion, he was given empiric antituberculosis therapy. The patient's condition improved dramatically over subsequent weeks. At 18 months review, he remained well taking prednisone monotherapy. Although culture negative, a diagnosis of probable mycobacterium infection was made on the basis of typical histological findings on liver biopsy, exclusion of other pathology and prompt response to antituberculosis treatment.[Ref]

Common (1% to 10%): Abnormal liver enzymesPostmarketing reports: Hepatitis, jaundice/cholestasis, severe liver injury such as hepatic failure and acute hepatic necrosis that may be fatal[Ref]

Consumer resources

Professional resources

Related treatment guides

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